Shore-protector



ST. JOHN CLARKE.

Patented Sept. 14, 1920.

2 SHEETS-SHEET llma ArToH/vfr ST. JOHN CLARKE SHORE PROTECTOR APPLTCATION FILED JAN. 14| 1918.

Patented Sept. 14, 1920.

2 SHEETS-SHEET 2.

ST. JOHN CLARKE, OF BOGOTA, NEW JERSEY.

sarei" asics.'

SHORE-PROTECTOR.

Application filed January 14, 1918. Serial No., 211,766.

To @ZZ ywhom it may concern.'

Be it known that l, Sr. JOHN CLARKE, a citizen of the United States, and resident of Bogota, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Shore- Protectors, of which the following is a specification.

My present invention relates to means for Y protecting beaches and banks, particularly beaches of sandy or shifting material exposed to the varying and alternating action of storms, tides and waves, but it is also capable of useful application to shores and banks of other materials exposed to erosion by less violent forces.

It includes as a central feature, a cellularv earth-trapping7 water-draining construction preferably made of reinforced concrete or similar material. Its novel features are of utility when built in a single structure and.

slab is in turn retained by the material from.

slipping downward along the slope'. lThus each section or slab unit may be independently supported by the surface on' which it lies even on a considerable inclinewithout the necessity of a foundation or other securing means. l

Each section consists of a relatively thin slab, structurally strengthened by integral downwardly projecting ribs, and formed Vwith one or more holes through which earth or sand may be filled in when the slab is laid, ribs downward, on the ground or beach surface to be retained thereby. v their function as strengthening ribs, the ribs serve as partitions and the slabs are so laid that there will be a series of these partitions extending lengthwise of the beach, thus subdividing and contouring the material of the surface into a series of approximately parallel earth or sand ridges which extend up- In addition to ward into the lspaces between the partition ribs. This tends to break up flow or seepageV i the slab. Hence I preferably provide a second series of depending partition ribs, preferably at right angles to those first mentioned, and consequently extend up and down the slope of the beach. For coiiveiiience the partition ribs extending lengthwise along the beach may be* termed longitudinal ribs or flanges while those extending up and down the slope may be termed transverse ribs or flanges.

lVhen slabs with both sets of partition ribsare laid in placethey constitute a system of open bottom'boxes or cell units, the walls of which are adapted to partition ofi' and subdivide the surface of the beach or bank to a desired predetermined depth, intoV frustunis of earth or sand of relatively small area. Each such frustum is substantially protected by the slab, the latter forming a fiat top or cover extending over a substantial part of the area of each cell but leaving an aperture through which the sand or other material may be introduced to fill in the beach surface to or above thetop of the cell.

The depth and spacing of the longitudinal partition ribs are predetermined with reference to the slope and shiftiness ofthe material, greater depth and closer spacing beingcrequired where slope is considerable or the material very shifting.

The size and locationvofthe aperture in the cell cover are predetermined with reference tothe angle of the shore or bank so that Awater finding its way into the open bottom of any cell, must flow upward in j Speciication of Letters Patent. Patgntgd Sein-, 141:, 1g20 v i I that cell in order to escape from the aperture in the cover. To this end, and for the better protection of the filling material, I prefer that the aperture inthe cover of each cell be located nearer the upper than the lower portion of the cover of the cell. The distance between the longitudinal partition.

ribs is preferably considerably greater than farther apart than the longitudinal ribs because there is less necessity for gripping the beach in a direction to prevent lateral shitting of the cell units along the beach and also in horizontal outline.

`because the wash along the beach is usually much less than the wash up and down the beach. This makes the open-bottom boxes or cells and sand rustums therein oblong For similar reasons the apertures in the tops of the cells may be correspondingly7 oblong without too greatly exposing the material of the beach to being washed out of the cells.

As will be evident from the foregoing, the width of the boxes or cell units is 'predetermined within limits by the slope of the beach and in most practica-leases, this dimension will be found to be such that a single cell will not have the weight and area required for stability against heavy waves. For this reason and also for convenience in manufacture, I prefer to embody the above describedstructural features in a monolith or slab large enough-.to include a considerable number of the longitudinal partition ribs. For structural strength with economy of material there should also be several of the transverse ribs so that the slab will comprise a considerable number of the box-like cell units, say 9 to i6 or eten 25. The slabs must notV be too big` ior structural rigidity however and as economy of material requires that the flanges be not too thick or too deep, the size of the slabs is limited. y

The above described slab structure is prei:- erably so laid-as to establish a condition of mutual cooperation between the beach material and the slabs so that the material willA retain the slabs against slipping down the slope while the slabs in turn will encourage deposit and discourage washing out of the material of the beach, the only opposition to the natural breaking of the waves being the upper and lower edges of the apertures in the tops ot the cells. vHence when used according to my preferred method, the slabs will be laid'on a slope bearing a definite relation to the natural slope of the beach and the natural angle of repose of the materialof which it is composed and the preferable slopes are less, usually considerably less than 30C. from the horizontal.

The above and other detailspf my invention as well as of its nature and objects may be more fully understood from the following description in connectionv with the accompanying drawings in which Figure l is a top plan view of a shore protected in accordance with my invention;

Fig. 2 is a vertical section on the line a'-, Fig. l;

Fig. 3 is a top plan view of a modified construction; and Y Fig. 4 is Va vertical section on the line y y of Fig. 3.

As indicated in Figs. l and 3, the slabs, l, l, l etc. are laid in horizontal rows extending along the beach as far as the shore protection is required. Similar slabs 2, 2, 2 and 3, 3, 3 and 4, 4, 4 are laid at successively higher levels so as to cover the surface of the beach, preferably from below low water level, indicated at A, up the slope of the beach B as far as protection is desired, preferably abovenormal high water mark.

The .slabs may be laid with their edges nearly or quite in contact with each other, as in Fig. 3, but I prefer to separate them slightly and also to shape their edges so that they will be less likely to bind against each other or become broken in case or" unequal settling or slight shifting of oneslab with respect to the others. Ereferably the joints or spaces between slabs in the successively higher rows l, 2, 3, 4 break -joints so that surf will be mostly up and down the slope transversely of the joints between the rows, and there is more tendency to wash thesand into these joints than out of them. Y

In case a bulk-head or break-water@ is employed the upper row of slabs may have their upper edges built or lcast into the struc ture as shown in Figs. 2 and 4.

In the form shown in Figs. l and 2 the slabs are constructed with longitudinalpartition ribs 6, 7, 8, 9, l0 land transverse ribs ll, 12, 13, 14 thus forming the bottom sur-A face of the slab into l2 box-like cell-units. The latter are oblong with their longery sides lengthwise of the beach so .that as shown in Fig. 2, each slab has four of the cell comwhich each compartment may be filled inA 'either by hand, as when the slab is first laid or subsequently by depositl and trapping of sand brought up by action of the surf.

For the above reason I prefer to make the slabs up in multiple units say about ten feet by ten feet or twelve feet by twelve feet for the square forms indicated in Fig. 3 or say eight feet by ten feet or ten feet by twelve feet for the forms shown in Fig. 1. In such case the slabs and partition ribs may be 2 or 3 inches thick. The depth of the ribs will be say eight to ten inches or more accord ing to the slope and material of the beach and in most cases the longitudinal partition rib may be spaced apart a distance y2 or more times the depth of the ribs.

It will be obvious, however, that the number of compartments and the sizev of the slabs may be greatly varied and that for some purposes it would be practical to use slabs say four feet by four feet having only a single compartment. In such case the partition ribs may be inset say six or eight inches from the edges of the slab.

It is not necessary that all of the ribs be of the same depth or thickness, since some of'them may be made deeper than others, for a portion or all of their length, for the purpose of increasing the structural strength of the slab, or for the purpose of deeper partitioning of the beach at certain points or in certain directions, or for the purpose of affording additional anchorage of the slab against slipping down the beach, or for protecting the edges of the slab, as for instance the lower edge of the lowermost slab of the upper edge of an uppermost slab.

Illustrative, examples are shown as applied to slabs l and 2. On slab l, the lowermost longitudinal rib is shown as extended downward a considerable distance as at 21 to afford protection against undermining. It may be braced by a bracket-like extension 22 of an adjacent portion of one or more off the transverse ribs. Slab 2 is shown as having its central longitudinal rib extended downward as at 23 and braced on both sides by bracket-like downward extensions 24, 25 of one or more of the transverse ribs. This would be useful. as additional central anchoring of the slab.

I prefer, however, that the slabs be of' equal size and the partition ribs of equal depth suitable to the slope and material of a given beach, since in case of any sli ht shifting or settling of the slabs the settllng is likely to be more uniform if the lower edges of the partitions lie in the same plane, than it is if one portion of the area of the sl ab engages the material of the beach more deeply than another portion.

It is impracticable to show or describe all of the possible conditions of the sand or other filling material with respect to the cellular compartments of the slabs. It will o be understood, however, that in many' casesv the slabs or some of them may be buried underthe sand, especially during weather favorable to beach building. Under certain average conditions, however, it will be eVident that Yeven dry sand will substantially lill the compartments as in Fig. 4. In Fig. 2, I have indicated the sand as having' been removed from certain of' the compartments of slab 2, so as to expose more or less of the rear surface of the uppermost partition of the compartment. In such case the compartment opening forms a trap well adapted to catchy sand carried up and down the slope by the breakers, and in case of seepage of water into the compartments from beneath, the sand will ynaturally settle out and fill the compartment while the water will escape through the opening in the top surface. The use of multiple compartments for a single slab averages the variable support which may be furnished. by a large number of vthe cells so that where some of themv are partially or even wholly empty the slab may be stillk adequately supported against settling by other cells which are more completely filled. In case of a wash-out completely un-` dermining one or more of the longitudinal partition ribs,'the cavity thus formed will` merely constitute* a larger trap adapted to be filled in either automatically or by hand through the slab openings in the same manner as single compartments are filled.

Slabs ofthe smaller sizes above indicated will not be too large for casting at a suitable central plant for transportation and laying upon shores at a distant point. I prefer, however, to employ theV larger unit, castingV them adjacent to the position in which they are to be used. For convenience in manufacture, it is preferable to mold or cast vthem flat face downward upon a suitable bed with box molds defining the partition ribs. The reinforcing rods 41, 41, 42, 42 may be most conveniently located adjacent the tops and bottoms of the partition ribs since this affords maximum transverse or truss strength for these members.

If the mold is located closely adjacent the place where the slab is to be laid, the latter may be of very considerable size since in such case the only handling the finished slab will require is turning over ribs downward off of the casting bed onto the beach where the compartments may be filled in with sand or other material which will soon settle into and form part of the beach surface.

I claim:

l. A shore protecting structure adapted to be laid on sloping shores comprising a slab formed on its under face with sets of intersecting partition ribs constituting open bottom cellular compartments and supporting the slab a considerable distance above the surface of the beach on which it is laid,

said slab ,beingvvformed'with filler openings through which each compartment may be filled. i y

2. A shore protectingstructure adapted to be laid on sloping shores comprisinga slab formed on .its under face with sets of intersecting partition ribs constituting open bottom cellular compartments and supporting the slab .a considerable distance above they surface of the beach on which it is laid, said slab being formed with filler openings adjacent theup-slope partition of each compartment.

3. A shore protecting structure adapted to Ybe laid on sloping shores comprising a slab formed on its under face with sets of intersecting partition ribs constituting open bottoni cellular compartments and supporting the slab a considerable distance above the surface of the beach on which it is laid, said slab being formed with illeropenings relatively remote from the down-slope partition of each compartment.

4. A shore protecting structure adapted to be laid on sloping shores comprising a .slab formed on yits under facewith sets of intersectin A partition ribs constituting open bottom cel ula-r compartments and supporting the slab a considerable distance above the surface ofthe beach on which it is laid,

Said slab being formed With filler openings adjacent the lip-slopeV partition o-fea'ch compartment and relatively remote from .the down-slope partition and from the side partitions thereof.

5. A shore'protecting yunit comprising. a slab having its under surface provided with longitudinal and transverse ribs, VandA a filling aperture lthrough which the space between partition ribs ymay be filled.

6. A shore Vprotecting unit comprising a slab having its undersurface provided with longitudinal and transverse ribs, and a filling aperture `through which Athe space between partition ribs may be lled, said apertures being much narrower than the space between the ribs.

r77. A shore protecting unit comprising a slab having its under surface provided with longitudinal and transverse ribs, and afiliing aperture through which the space between partition'ribsmay be filled, said apertures being much narrower than vthe space between the ribs and located nearer one rib than the others.

Si ned at New York city, in the vcounty ofi ew York and State of New York this 12th day of January, A. D. 191s,

sT. JOHN CLARKE. 

